Clothes dryers typically provide a rotating drum perforated with openings to allow forced airflow through the drum walls while the clothes are tumbled within the rotating drum. The drum is normally held within an appliance housing to rotate along a horizontal axis to promote tumbling action while the drum opening is covered by a housing door to retain the clothes therein. The forced air through the drum walls may be heated by an electrical or gas heating element to increase the drying capacity of that air. Humid air, after passing through the clothing, is normally exhausted out of the dryer through an exhaust duct leading outside of the home or building.
Clothing dried in this manner will often release fabric threads and the like which form combustible lint which may be trapped in a lint screen to be periodically cleaned by the user. The presence of heated air and the combustible material of the lint, the latter of which may accumulate throughout the dryer particularly if the lint filter is not cleaned or replaced, and/or the cleaning of clothes containing combustible fluids can on rare occasions cause a dryer fire in which materials within the dryer begin to burn.